The Mouth-covering technique was memorably deployed by Angela Merkel and Emmanuel Macron at a summit in October to mask their discussions with Theresa May (pictured)
How far would you go to wrong-foot lip readers?
The recent image of the German and French premiers huddled around the British prime Minister as they arrived at a venue together sparked widespread mockery on social media - with speculation rife over what gossip they were passing on.
However, some observers believed that they were actually talking about the Iran nuclear deal.
Manchester United Star Paul Pogba (left) deployed his shirt as s shield as he muttered to Leicester's Riyad Mahrez at the end of a game in August
Politicians are now increasingly deploying hands over mouths to avoid lip readers. There is no doubt that the technique has spread from sports where teams hide secret chats from cameras.
Soccer stars have been habitually covering their mouths as they talk to each other for years, to avoid their words being caught by TV cameras.
Doubles tennis players and baseball teams also take the evasive action for fear of opponents anticipating their tactics.
Mouth-covering in soccer became more popular after the Brazil team's private chat was exposed during the world cup in the South American country in 2014.
A TV channel revealed that coach Felipe Scolari barked at his players during a match against Croatia, which they eventually won 3-1: "We are playing at home. What is this?"
Other proponents of mouth-covering include Spain's finance minister Luis de Guindos (pictured at an EU meeting in May)
A former special adviser to the prime minister said:
'Covering your mouth is a no brainer when you are dealing with high stakes issues of huge diplomatic and national importance.
'One misplaced word picked up by the media can trigger a diplomatic storm or result in key negotiations collapsing.
'There are often no hiding places at these summits.
'Every single piece of body language is being picked up and analysed by the media and other world leaders and you don't want your negotiating tactics being played out in public.
'These summits also have microphones and cameras dotted everywhere picking up the smallest movements so covering your mouth is not a bad insurance policy. '